Cole's feels responsible for his friends kidnapping. They didn't want to go trick-or-treating at the house and he talked them into it. When an opportunity arises for Cole to find them, he ends up on an adventure where he discovers people from other kingdoms with different powers and rogue magic. This is the first in a series where more questions come up than are answered. It sets up for the next book that I expect will do more world building and explain the complex dream world Cole finds himself in. As is, this story had an unfinished feel to it.
I found myself enjoying the action but not always understanding the governing structure of the rulers. Each kingdom has a special power and the High King is trying to control all the powers, but I'm not sure what those powers are in every kingdom. The High King doesn't interact with the characters and is an absentee villain. His flunkies do his work for him. There is a romantic triangle between three of the characters that causes them to argue much of the time.
Cole has some latent power that I hoped would flare into existence but that must be in a sequel. The overarching message is Cole must save his friends. The author never quite explores in-depth the illusion of dreams. His alternate world has a surreal feel, but the abstractness doesn't resemble any message. Mull knows how to build worlds and I like his monsters, but it seems there were too many holes in this plot. Guess I'll have to read book 2. I like Mull's writing. It's entertaining and very creative.